Grommet construction



oct. zo, 1936.

N. LAM PORT GBOMMET CONSTRUCTION Filed April 5, 1935 INVENTOR. l /Va .Ed/)Wwf v ATTORNEY;

Patented Oct. 20, 1936 oFEIeE V2,057,961 GROM'MET CONSTRUCTION Noah Lamport,

Application. April 3,

1 Claim.

This invention relates to improved grommets.

The invention includes two hollow rivets, each having a tubular shank portion with an exterior peripheral flange at one end, the shank of one rivetrdifffering in diameter from that of the other, in order that said shanks may be secured together in a telescopic relation to each other,

when said rivets are pressed together endwise,

the outer end portion of the shank of each being lo deflected outwardly against the flange of its fellow rivet in a novel and improved manner,

thereby completing the article as an applied fastening means.

An important object of the invention is to provide a two-part grommet structure which, by the use of automatically operating dies, can be more readily applied to superimposed pieces of fabric, or to other sheet materials, as a fastening means, or which may be used to form eyelets in single layers of sheet material.

Hitherto difculties have been encountered in automatically feeding to the applying dies fastening devices of the kind to which this invention pertains, and at the same time securing an entirely satisfactory union between the parts thus fastened together. It is an object of the invention to overcome these defects.

Other objects, advantages and features of the invention may hereinafter appear.

Referring to the accompanying drawing, which illustrates what is at present deemed to be a preferred embodiment of the invention,

Fig. 1 shows the applied grommet in a Vertical mid-section.

Fig. 2 is a Vertical mid-section illustrating the first part of the riveting or peening over operation.

Fig. 3 is a fragmental plan View of the assembled grommet.

Fig. 4 is a vertical mid-section showing the male and female elements in their guides positioned to be led up to the die elements which unite them.

Fig. 5 is a vertical mid-section illustrating the positions of the dies near the beginning of the peening over or clinching operation, on line 4 4 of Fig. 6.

Fig. 6 shows the general arrangement of the feeding members, die members and grommet elements preparatory to being applied to the sheet material.

Referring in detail to the drawing, the male grommet element, in its unmodified condition, comprises a tubular shank 'l furnished at one end with a peripheral outwardly directed con- Los Angeles, Califl 1935, serial No. 14,491 (o1. 2li-141) cavo-convex flange 8 having crimped thereinto a circular groove 9 or'line of indentation which projects towards the end of the shankv l which is farthest from the flange, and which is concentric to said shank. Said iiange is provided along its periphery with a lip H the outer edge of which also forms what may be termed a line of indentation, and which is directed toward the same end of the shank i as the indentation 9.

The female grommet consists of a shorter shank portion lll the internal diameter of which is slightly greater than the outer diameter of the male shank l. Said shank lli is surrounded by a concavo-convex flange l5, the radial extent of which is much greater than the length of said shank. Said flange l5 has, opposite to the shank llt, an annular shoulder i6 which is positioned to cooperate with the indentation 9 around the male element, and with an annular outer lip edge or indentation l'l to cooperate with the lip edge Il. The two sets of annular lines of indentation cooperate to grip between them the fabric or sheet material 2t. Each of the two inner lines of indentation (9 or 16) projects farther inwardly into the fabric than the adjoining metal on both sides thereof.

The means to automatically feed the male and female die elements to each other is not shown in detail, but such means will include an upper guide 2l for the male member and a lower guide 22 for the female member. After these guides have brought said members into the proper positions the male member will be acted upon by the die 23 (see Fig. 6) and punch 24 which moves with said die; while the female member will be supported by the lower 'die 25. T'he punch 24 terminates in a conical apex 28.

The lower die 25 surrounds a lower circular follower 2S which has a central bore or recess 3B to cooperate with the conical apex 28 of the punch. Said recess 30 is formed in a rise 3l central to said follower, and is surrounded by a groove 32 which, as viewed in cross section is properly curved to effect the desired peem'ng or deflecting operation upon the shank of the female grommet element. The plunger 29 is movable independently of the lower die 25, and it is to be understood that the various feeding, guiding and peening elements will be constructed and arranged to cooperate properly, as such constructions and arrangements come within the range of the skill of mechanics skilled in the art to which the invention pertains.

In the completely applied grommet the shank of the female element is rolled outwardly against itself as indicated at in Fig. 1. The fabric 20 abuts against one side of this rolled part, and the shank of the male element has an outwardly deflected and peened over part 36 which abuts against the side of the part 36 which is opposite to the fabric 20.

The structure of the applied grommet is reinforced by reason of the fact that the edge of the peened over part 36 of the male shank fits within and abuts against the inner side of the line of indentation which forms the annular shoulder I6 in the ange of the male element.

Viewed as a method, the invention includes the following steps: Bringing the material and the female grommet element into a flatwise contacting relation to each other with the shank of the female element directed away from said material, then projecting the shank of the male element through a hole cut in said sheet material and the opening of the female element from the side of the sheet material opposite to the female element, and nally advancing said male element farther toward said female element to grip the sheet material between said elements and simultaneously peening outwardly the shanks of both of said elements thereby bringing the peened over part of the male element into an exterior gripping relation to that of the female element.

I claim:

An applied grommet structure of the kind described which consists of a female element having at its center an opening and around said opening a projecting hollow shank portion which is outwardly peened over, and a male element which has a hollow shank extending through said opening and female shank, said male shank being outwardly peened over around and against said shank portion of the female element, and sheet material which is gripped between said male and said female members, each of said members having an outwardly directed peripheral flange with a circular line of indentation which is directed towards a corresponding line of indentation in the other ange, the aforesaid peened over edge portion of the male shank engaging and reinforcingthe line of indentation in said female element. Y

NOAH LAMPORT. 

